


Vicarious Atonement

by MissKierie



Category: Undertale (Video Game)
Genre: Anal Sex, Bad Jokes, Bad Puns, Blood, Death, Death Threats, Ecto-Penis (Undertale), Ecto-Tongue (Undertale), F/M, Masturbation, Multiple Timelines, Nervousness, Nipple Play, Other, POV Female Character, POV Multiple, Public Sex, Rape/Non-con Elements, Reader Is Not Chara, Reader Is Not Frisk, Reader-Insert, Rough Sex, Sadism, Slurs, Vaginal Sex, Violence, noncon
Language: English
Status: In-Progress
Published: 2017-04-21
Updated: 2017-07-25
Packaged: 2018-10-22 00:58:04
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 5
Words: 3,992
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10686492
Author URL: https://archiveofourown.org/users/MissKierie/pseuds/MissKierie
Summary: During a Pacifist run in Undertale, the player/reader notices a few sadistic features in Sans’ character, and calls him out on it. He assures the human thathe has no idea what they're talking about.Through this kinky, masochistic, sexually enthusiastic human, Sans falls down the rabbit hole of BDSM, discovering new things about himself and his place in this timeline.The title is from the Mars Volta song, “Vicarious Atonement.”





	1. benign

**Author's Note:**

> new fic, focusing on character interaction and personal development. might change POV, from the reader/human to Sans.
> 
> i'm excited to go on a new journey with you all <3

**Summary for the Chapter:**

> On your second date with Sans, he says something unexpected.

**Notes for the Chapter:**

> PLEASE NOTE: capitalization in this story (or lack thereof) is intentional.

**“. . . Y o u ’ d b e d e a d w h e r e y o u s t a n d.”**

The room is silent. You can hear your heart pounding, you hold your breath. Sans stares at you from across the table. His eyes, empty. 

After a few moments, you swallow loudly, your throat dry. He just threatened to kill you. This seemingly mellow skeleton just said you’d be dead by his hand if it weren’t for a promise.

His static grin switches a little at the corner, white lights returning to his sockets. “hey, lighten up, bucko,” he says cheerily, startling you, “i’m just joking with you.” He throws you a playful wink, arms returning casually to the table. 

You lean away, face still frozen with shock. He invited you to this date at MTT resort. He just said he’d kill you. And now he’s trying to play it off like it’s all a big joke.

“besides…” he continues, index finger poking at a dining fork in front of him, “haven’t i done a great job protecting you? i mean, look at yourself. you haven’t died a single time.”

Throw him a look of disgust— not only have you died several times, he also has the gaul to JOKE about it!

“hey, what’s _that_ look supposed to mean?” His smile deepens in it’s contempt, “am i _wrong?_ ”

“You sick **FUCK!** ” you suddenly spit out, grabbing the edge of the table, pushing it towards him with a noisy _skree_. Boiling with rage, you continue, uncaring that you’re now the center of attention, “what the **fuck** is wrong with you?! **Why** did you tell me that? What is even the point—“

_He was trying to scare you._

Sans just stares at you, expression unmoving. He blinks. And waits as you lean back into your chair with a sigh. This sicko was just trying to scare you, to get a reaction out of you. His voice dipped low, his energy darkened, he threatened you, and it made you want to _writhe_ beneath him. 

You cross your legs and put on a coquettish smirk, voice cracking a bit as you say, “I didn’t know you felt that way about me, Sans.”

“what,” he immediately responds.

“That’s pretty kinky, death threats on the second date. Just how much of a sadist are you?”

The skeleton sneers and looks off to the side, “listen, kid, i don’t know what you think is going on here, but—“

“Was it _fun?_ ” you almost whisper, now loaded with desire, watching him unfold is just too delicious, “coming up behind me outside the Ruins? You scared the shit out of me. Why exactly… did you do that?”

He’s silent. Slowly, he puts his hands back into the pockets of his blue jacket. “… i don’t think you know what you’re getting yourself into,” he mutters in the same low tone, “ _little girl._ ”

You shudder, hands beginning to tremble, so you pull them into your lap so he can’t see. “Sh-show me,” you challenge.

Sans closes his eyes and stands up, taking a few steps away from the table. His back to you, he starts laughing, a fluttering _heh heh heh._ “meet me in the alley,” he says. Then he walks away. 

**OH FUCK.**

**Notes for the Chapter:**

> ~~look up the lyrics to vicarious atonement for foreshadowing~~


	2. Impetus

**Summary for the Chapter:**

> You meet Sans in the alley.

**Notes for the Chapter:**

> PLEASE NOTE: use of capitalization (or lack thereof) is intentional. this is Sans' point of view.

[♫](https://youtu.be/e1Jbes2NLf8?list=PL60408EBD7150DDA5)

what the **fuck** were you thinking, playing along with her? she’s manipulating you. of course, she followed you. little slut, she’s been eyeing you up from the very beginning. her breath is short, she’s staring at you with anticipation as she pushes herself against the alley wall behind her. you move towards her and she whimpers. heh.

god… what have you gotten yourself? whatever.

“do you like being scared?” you ask as you step into her personal space. she lifts her hand to block you and you grab her wrist. she whines again, face flushing with color, hah hah. too easy.

“D-do you like _scaring_ people?” she fires back, her nervous expression betraying the prodding question. she yanks her arm away from you and you let her go. 

“…” you put your hands on her, touching her for the first time, other than that one handshake. you grope her hips, feeling the flesh squish and dimple. she moans immodestly and runs her hands up your arms before wrapping herself around your neck.

anxiety surfaces. she’s touching the bones of your cervical spine, bringing you into her, smelling so good, feeling so real and… **vulnerable.** your arousal is becoming obvious, magic centralizing between your legs and across your cheek bones. she leans her head back when you take ahold of her breasts, as if to invite you to her neck.

she exhales loudly as you press your teeth into her throat, her pulse is racing, her hands shaking along with yours. “Maybe,” she continues with an airy voice, “you just like scaring humans.”

your phalanges slip into the back of her pants, taking ahold of that beautiful ass, pulling her crotch into your erection. she lets out a sound of surprise at the bulge in your shorts, then grinds herself against it curiously and you have to chuckle. she wants it baaaad.

“i think you should quit worrying about me,” you mumble into her neck, “and focus on yourself. you’ve got some issues, kid.”

she giggles, flaring foreign anger inside you. slam her into the wall with a hearty thrust of your hips, phalanges digging into her asscheeks. “i’m serious,” you say, “lookit you, all flustered over a skeleton who almost killed you. pretty freaky.”

“Ooh, fuck, **Saaans~** ” she purrs next to your skull and god, you’re losing control. “Hurt me, fuck me. Make me your _bitch._ ”

**_what the fuck._ **

you stumble back, hands leaving her. instinctively shove your hands into your pockets and take another step away.

she just stands there, supported by the alley wall, looking at you with big, wet, hungry eyes. slowly, she pulls her top up over her breasts, showing you the curvature of her body in her bra before she pulls that up too. her tits pop out, she cups them and runs her thumbs over her nipples. they’re hard and they tug up a bit as her fingers drag across them. she pinches one.

…

you let out a low, long sigh as you gape at her. she smiles at you and raises an eyebrow.

“alright, babe… but don’t say i didn’t warn you.”

**Notes for the Chapter:**

> next chapter will probs be out soon. sorry for all these cliffhangers lol i know u want some action.


	3. Agog

**Summary for the Chapter:**

> What the hell is that in his pants?

With that terrified look on his face, you half expected him to teleport away. But he didn’t, he paused and watched you, his shoulders heaving as if he had lungs, as if he was frantically breathing. His grin never moved. In fact, it stretched as you played with your nipples, exposing more of his teeth than you’ve ever seen. Looks like he has a few sharp ones in there. Hmm.

“alright, babe,” he finally says, “but don’t say i didn’t warn you.”

[♫](https://www.youtube.com/watch?v=emU2aoj8CIQ)  


This intensity of his tone makes you giggle— another threat! This guy sure likes the sound of his own voice. 

Your eyes watch the budge sway slightly between his legs as he comes up to you again. You weren’t expecting him to have anything down there… he’s a skeleton. _What is it?_ You’re so curious.

He grabs your wrists and pulls them away from your chest, replacing them with his own. His bones are hard, smooth, and warm as they feel the weight and texture of your flesh. He pushes your tits together, as if to compare them, and asks, “what do ya call identical boobs?”

You raise your upper lip and offer a mock chuckle at the joke, shaking your head as you let your hands rest on his shoulders. “Do you tell jokes to help yourself relax?”

He pinches your nipple in response, making you yelp. “ _identitties_ ,” he says, his gaze turning positively lecherous. “you shouldn’t be laughing at the monster who’s got you pinned to the wall.” His fondling gets progressively more assertive, more _eager_. He circles your nipples with his thumbs, pulls and pushes, gripping so hard it hurts. 

“Sans,” you respond breathlessly, already so turned on, you want more, “what’s that glowing in your shorts?”

Teasing you, he presses himself into you again, rubbing something hard and cock-shaped against your thigh. “mind your own business.” Then, first the first that you’ve seen, he’s opening his mouth. There’s a flash of light blue and a wet gleam on his small fangs, then he takes your breast inside. You gasp, staring at him with wide eyes as something feeling like a tongue laps at you. “fuck, you taste good,” he mumbles into your flesh.

“Ooookay, you have a **tongue!** ” you exclaim, tittering again, overwhelmed, he’s just full of surprises. Fuck yeah, that means that probably is a dick humping against your thigh, slipping closer to your crotch with each movement. You spread your legs, genitals so swollen, so wet, you need stimulation. “Touch me,” you whisper.

Sans moves from one tit to the other, leaving a clear patch of saliva on your skin before rubbing it all over your chest with his hand. “what’s the magic word?” he asks as he looks up at you, teeth carefully closing around your breast, sharp canines digging.

“Aaahhn, _please!_ ” 

Both of your hands fumble around, you struggling to undo your pants as he tries to stoke your groin. He laughs nervously as you pull your pants down, seeming to not expect that.

“oh, _wow_ , you’re gonna just, uh,” he pulls away from your chest and leans back, white pupils shrinking as he gapes at your underwear. 

“Look at how wet you’ve got me,” you chime as you pull the front of your panties out, showing him the damp spot on the crotch and the shine on your labia.

He chokes on his own breath and reaches up to rub the back of his skull. “that’s, um…” 

You just smile at him reassuringly and let go of your panties, allowing him to take his time, or stop, whatever he needs. He takes a deep breath and slowly puts his left hand between your legs. Phalanges cup your sex, sliding up the mound before going back down. You encourage him, whining loudly and bucking your hips into his hand. He pushes into you, too hard, and you tell him, “aaah, be gentle… your bones are hard.”

“not the only thing that’s hard,” he says in a different tone, deeper, and he takes your dominant hand and slips it down his shorts. He guides you to wrap around his shaft and start a slow, up and down, rhythm. His ‘dick’ is firm, but feels almost like jelly, foreskin sliding up and down. It’s a little wet, and very warm. Sans exhales next to your face and closes his eyes, looking totally blissed out as he continues rubbing your panties into you.

“God, I want you to fuck me so bad,” you admit, closing the gap between you to kiss his smile. 

“here, in this alley?” he breathes at your face, smelling musky, “mmm, okay, kid. as long as you don’t surprise me with a bill after.” You kiss him harder and he whines, leaning in, taking your face in his other hand, holding you close as he opens his mouth and pushes his tongue into you.

You pull his cock out as he yanks your underwear down to your knees, where they soon fall to your ankles. He’s literally glowing blue, his dick, his cheekbones, and something pounding in his ribcage. You lift one leg and rest it on his iliac crest. He grabs a hold of your hips and you guide him to your pussy. 

He looks at you and gives you an odd grin.

“What,” you ask, casually rubbing him against your damp crease

He starts slowing pushing into you, the heat incredible, and he says, “why did the skeleton have to use magic to fuck the human?”

You groan, both at his joke and the feeling of your body stretching to accommodate him as he inches inside. “ **Saaaaans** ,” you gripe.

“he didn’t have any _guts._ ”

**Notes for the Chapter:**

> sans is determined to get the last word in every chapter.
> 
> sorry i'm stretching the scenes out so much >_> it's just how this story is happening. shit gets REAL next chapter.


	4. Breaking Point

**Summary for the Chapter:**

> what did you think would happen?

**Notes for the Chapter:**

> WARNING: EXPLICIT NONCON/RAPE in this chapter. sorry.

[♫](https://youtu.be/Zg6svO2AQHw?t=4m47s)  


Vision blurring, the orange light coming in through the window turns red as blood pours down your face. You drop the knife and it lands on the marble floor with a loud clatter. 1 HP left. Breathing heavy, you wait for that final femur bone to rip the life from you.

This is the 12th time Sans has ended your game. But unfortunately, for you, Sans is keeping you alive. For some reason.

He does something completely off script; he stomps towards you, grabbing you by the hair and throwing you against one of the pillars in the judgement hall. You cry out in pain as your bruised body collides with the hard stone, but you’re soon silenced as he’s behind you, phalanges around your neck.

“What are you doing,” you choke out, hands shaking as you cling to the column for support. “Just get it over with.”

“no point,” he says, voice as normal as ever, “i can see in your face that you’ve died multiple times. maybe eleven? guess i’ll have to do something _else_ to teach you a lesson.” 

His voice deepens and rumbles during that last sentence and it stirs something sexual inside you. You inhale sharply as he reaches around your body, unbuttoning the top of your pants. Pushing against the pillar, you try to slip away, but the alien points of his pelvis thrust into your ass and pin you. Real fear materializes, unable to believe that this is happening. No, no, he’s killed you eleven times!! He’s supposed to say, _‘let’s just get to the point,’_ and kill you! How is he going against his own programming?

“eyes forward,” Sans commands as he tightens his hold around your neck, “and don’t say a fuckin’ thing.”

Your hands shake as they grasp the pillar, unwanted arousal flaring when his boney pelvis thrusts into your ass again. His other hand unceremoniously dives down the front of your pants, exploring, rubbing between your legs until you retch out a stifled moan.

“you’re enjoying this, huh?” he sneers, pressing what feels like teeth at the nape of your neck, his breath, hot. “pretty freaky, kid.”

His hand around your neck, now covered with the blood leaking from your head wound, slowly slides down to your chest and gropes at the flesh feverishly. His other hand has discovered your clit and he rubs at it until your desire is palpable, all the while grinding what feels like a cock against the seat of your pants.

“alright, you seem more reasonable now. how about an apology?”

You grin wickedly, eyes staring directly into the swirling details of the rock pillar. You think about how many times you’ve wiped this game clean, how many times you’ve killed Papyrus, and how many times Sans has killed you. “I don’t think so,” you reply, voice cracking with how dry your throat is.

As if to change your mind, Sans yanks your pants down with one hand and thrusts into you again. He spreads your asscheeks and you can feel a warmth at the base of his pelvis pressing against your hole, the familiar feeling of a hard cock making you shiver. 

“you sure about that?” his voice echoes in a way that makes your skin crawl.

If he’s going to do what you think he is, this is going to hurt. In an all new way, that you won’t be able to restart away. Everything about you tells you to apologize. Everything except your determination and your contempt for this monster.

“Why,” you start, swallowing, “why did you _let me_ kill your brother?”

Immediately, he releases your breast and grabs a fistful of hair, mashing your forehead into the column. You scream, head spinning, suddenly filled with the animalistic urge to escape, kicking and trying to reach at him. But he pins you once again, this time with his cock plunging into your dry asshole.

“ **GAAAHH!!** AHHHhahahh, **WAIT!** ” you have to screech as he immediately starts fucking you, spreading, tearing, pulling at the sensitive tissue of your canal. “WAIT, _PLEASE!!!_ ”

“don’t fucking talk about my brother,” Sans grunts, “hah, damn, that’s tight. how’s _that_ feel, huh?”

You’re bawling, trying to reach at him and failing, body flooding with so many stress responses. 15 thrusts in, the pain starts to fade, blood providing some lubrication, your body adjusting to the relentless abuse. His cock pounds so hard, you can feel it through all your internal walls, pushing against your g-spot. You whimper, both in pain and pleasure, and the skeletons laughs at you.

You think, again, about how Sans warned you before reaching Snowdin. He knew you were killing everyone. He said, _‘you’d be dead where you stand.’_ But look at you, alive, his brothers dust on your hands, as he fucks you in the last corridor for all you're worth.

“BUT YOU **DID!!** ” you froth, body not bothering to swallow as it focuses on the attack, so the drool just spills down your chin. “ _YOU LET ME KILL HIM!_ YOU COULD HAVE STOPPED ME!” He bashes you into the pillar again, pushing against your shoulder blades painfully. You turn your head enough to meet his magic eye, and you smile. “ **Why didn’t you?!** ”

He growls and looks down at his dick pummeling you before he finishes. The magic is searing as it blasts against your brutalized insides, filling you completely as Sans sighs with satisfaction. He pulls out and you can feel your ass gaping. He just stands there, hands still pinning you, and you crumple as the adrenaline begins to leave your body.

So humiliated and broken, you peep out, “I’m sorry.”

“get fucked,” Sans says, raising his left hand, giant animal skull materializing above you. It opens it’s mouth and— **ppwwweeeeEEHHH BWOOO _OONNNNNNN!!!!!_**

Your soul splits apart into nothingness.

##  **GAME OVER**

**You’re going to be alright! (Your name)! Stay determined…**

. 

..

...

..

..

.

Sans' flashing blue/yellow eye flares up suddenly as he fucks you against the alley wall. He throws his head back and steps away, cock dissipating. Sweaty and starting to shake, his empty sockets stare into nothingness and you just stand there, breathing heavily, flushed, wondering what the hell just happened.

“i…” the monster starts, left hand holding his eyes as if it hurt. “uh, sorry. i’ll see you later.” The guy walks offscreen, disappearing, leaving you alone, half-dressed and horny in the shady alley. 

Take a moment to center yourself, then slowly start to put yourself back in order. You’re alone. Well. You don’t know _what_ happened. But you do know one thing for sure.

You aren’t leaving the underground any time soon.

**Notes for the Chapter:**

> THIS CHAPTER WAS GREATLY INFLUENCED BY [THIS GREAT FIC](http://archiveofourown.org/works/5444432)  
> 


	5. soft

**Summary for the Chapter:**

> Welp, better masturbate

**Notes for the Chapter:**

> sorry for the long pause -w- thank you for coming back!

c’mon, sans. get the fuck outta there. shortcut, shortcut. in snowdin. go home, shuffle upstairs, and lock yourself in your room. you collapse against the back of the door, sliding to the floor slowly as you stare up at the ceiling.

what the **FUCK** was that?!

you saw an image. an intrusive thought. something. the human, her back facing you, your cock penetrating her as she screamed for you to wait. you could almost feel the tightness of her hole, smell her sweat and musk. she turned around to face you with a sick look on her face. the face of someone who has lost everything, is completely broken, and _happy_ about it.

your magic is still blazing and your erection just won’t stop throbbing. fuck, you gotta do something. pull your dick out and oh fuck… it smells like her. a few streaks of her wetness still leave a faint shine across your shaft. 

shit, she wanted it. she was right there. you were already inside her. you could have done anything, made her cum, but you chickened out. you hide your face in the sleeve of your jacket as you mindlessly play with yourself.

what is wrong with you. WHAT IS WRONG WITH YOU? why would you imagine something like that? there was blood, too. she was crying. but oh, that sweet look of discomfort. you’re so slouched against the door at this point, you might as well be lying down. your phalanges aren’t enough, they’re too hard, you want something soft, to imitate her fleshy insides. 

you grasp at the mess around you blindly, your dick is too wet and the tension is too much to pause, until you find what is probably a pillow. roll over and trap it between your legs, both your arms moving to the dirty carpet. you bite your sleeve to muffle your grunts as you thrust into the fabric. it doesn’t feel like her, but it’ll do. soft, soft feather and cotton mold around your magic and haha, it’s starting to feel really good.

she technically hasn’t done anything to you, or anyone for that matter, to warrant such perversion. but what she said, fuck: ‘make me your bitch.’ you let your mind slip into depths that you only visit during masturbation. her, bound, broken, speechless, humiliated, covered with monster cum and tears. she’s scared and she gave up trying to get away hours ago. haha, fuck yea, that’s so fucked up. you barely even know her.

thrust your left hand under yourself to fist your own pelvis and stimulate that back of your pubis. the bone grinding on bone hurts slightly, but you deserve it, and it makes your cock feel unbearably sensitive. you suddenly feel very submissive, rutting into your pillow, in so much pleasure you’re helpless. she would love you like this, wouldn’t she?

all the tension and days without touching yourself finally explodes out of you. fevered magic pumps into your system, flowing through your bones and finally bursting from the tip of your cock. you ride out the euphoria, gritting your teeth to keep quiet.

thrust thrust… thrust…thrust… and it’s gone. you pull you hood up over your head and push the soiled pillow aside. exhilaration fading. guilt setting in.

…

you wonder if papyrus has any dinner plans. 

**— — — — —**

Your game reloads. Last corridor. 13th time. Unsure whether it’s real or just a side effect of your previous game, your ass aches. Your cunt tightens at the memory and your stomach drops.

Slowly turn your head to the side and he’s there, at the other end of the room. Sans, only a vague figure, his outline bleached from the sunlight coming in from the huge windows. You stare at him for a few minutes, to see if he’ll do something different. He doesn’t, he just stands there, occasionally shifting his weight from one foot to the other. 

You stomp down the hall and bellow out before he can say anything, “DO IT AGAIN!”

He doesn’t respond. He blinks.

“Again!!” You reach out to him in desperation, as if that alone will make him understand.

Silence. Birds chirping. 

“… let’s just get to the point,” he sighs.

— — — — — 

You let your dominant hand rest against your throbbing genitals. Sans left you high and dry. Someone had to finish the job.

With your other hand, you click on Papyrus’ number from the list of contacts on your cellphone. Ring… Ring…

“YOU’RE AT MTT RESORT?” His voice is so loud, you have to hold the phone a few inches away from your ears. “WHY??? MY GARAGE IS ALWAYS OPEN TO YOU!!”

“Yeah?” you say in a voice way too seductive than you meant it too. Clear your throat and pull your hand out of your pants. Dirty girl. “Uh, I think I’ll take you up on that offer! I’ve decided to stay in the underground for a while.”

“OH, THAT’S GREAT!!! I WAS HOPING YOU WOULD CHANGE YOUR MIND!”

He starts going on about actives he has planned. Sleep overs, cooking dates(platonic), 6am jogging… You let him talk as your mind wanders. Why did Sans leave? Is it going to be hard to get in his pants again? Mmm, what else can he do with that tongue?


End file.
